This invention is directed to certain surfactant compositions and to methods of reducing the surface tension of aqueous solutions with the compositions. More particularly, the invention is directed to new quaternary ammonium functional siloxanes.
A surfactant is a compound that reduces surface tension when dissolved in a liquid, decreasing the attractive forces exerted between molecules in the surface region of the liquid, enabling the liquid to spread more readily. Liquids with low surface tensions spread more readily than water, while mercury a higher surface tension liquid spreads less readily than water.
Surfactants exhibit combinations of cleaning, detergency, foaming, wetting, emulsifying, solubilizing, and dispersing properties. They are classified depending upon the charge of the surface active moiety. In anionic surfactants, the moiety carries a negative charge as in soap. In cationic sufactants, the charge is positive. In non-ionic surfactants, there is no charge on the molecule, and in amphoteric surfactants, solubilization is provided by the presence of positive and negative charges in the molecule.
Quaternary ammonium functional siloxanes are not new in the art. For example, in United Kingdom Patent No. 1,549,180, published July 25, 1979, there is described certain fabric conditioning compounds which are dialkylquaternary ammonium terminated linear polydimethylsiloxanes. The compounds of the present invention, in contrast, are monoquaternary ammonium functional polydimethylsiloxanes, and are trialkylsiloxy terminated rather than dialkylquaternary ammonium terminated as the materials in the '180 patent. United Kingdom Patent No. 1,006,729, published Oct. 6, 1965, is directed to certain surfactants which are trialkyl mono(polysiloxy) ammonium chlorides. However, the compounds of the present invention can be distinguished in that the compounds are dialkyl di(polysiloxy) ammonium chlorides, as well as some species which are monoalkyl tri(polysiloxy) ammonium chlorides. Thus, it should be apparent that the present invention is directed toward new and novel compositions of matter not previously known in the prior art.